Polyamide resins (to be abbreviated hereinafter as "MX nylon") synthesized from xylylenediamines composed mainly of m-xylylenediamine and alpha, omega-linear aliphatic dibasic acids have attracted continued industrial interest as high-modulus fibers or biaxially stretched films. Since in their non-stretched state, they have the property of becoming brittle and being broken at ordinary temperatures and have poor impact strength, no industrial value has long been found in their non-stretched products.
Miyamoto et al. found that the above defect could be remedied by blending glass fibers, etc. with MX nylon, and proposed in U.S. Pat. No. 3,962,524 a polyamide molding composition comprising MX nylon and glass fibers as a molding material having excellent chemical, thermal and mechanical properties. Miyamoto et al., in order to remove the defect of the poor operability of the above molding composition in an molding operation, further proposed a polyamide molding composition comprising an admixture of glass fibers, nylon 66 and MX nylon in U.S. Pat. No. 3,968,071. Injection-molded articles obtained from this molding composition still have the defect of great warpage, and when these molded articles are coated with a high-temperature curable paint such as an alkyd paint, the adhesion of the coated film to the molded articles is poor. These defects still remained uneliminated.
On the other hand, an acrylonitrile-styrene copolymer (to be abbreviated hereinafter as "AS resin") has recently attracted interest as a transparent material comparable to polystyrene, polycarbonate, polymethacrylate, etc. because in addition to its high transparency, it has mechanical properties, chemical resistance and stress cracking resistance in a relatively well balanced state as an industrial material. However, for application to machine parts, its impact strength, chemical resistance and thermal resistance are still insufficient. Glass fiber-reinforced AS resin has considerably improved strength characteristics but even when it has a high fiber content of about 20%, it has a heat distortion temperature of only a little over 100 .degree. C. Because of such a low heat distortion temperature of the AS resin, it is impossible to coat its molded articles with high-temperature curable paints.